The invention relates to a positive-working radiation- or light-sensitive mixture. More particularly, the invention relates to a mixture which comprises:
a) a water-insoluble polymeric binder which is soluble in aqueous alkaline solutions and PA1 b) a 1,2-quinone diazide or a combination of PA1 R.sub.2, R.sub.3, R.sub.4 are identical or different and denote hydrogen, or alkyl or aryl groups, PA1 R.sub.5, R.sub.6 and optionally R.sub.7 are identical or different and denote hydrogen or halogen atoms, or alkyl, aryl or alkoxy groups, PA1 X denotes the atoms necessary to complete a mononuclear or polynuclear carbocyclic aromatic ring system, and PA1 n is 1, 2 or 3. PA1 R.sub.l denotes a hydrogen or halogen atom, or a cyanide or a C.sub.1 -C.sub.6 alkyl group, PA1 R.sub.2, R.sub.3, R.sub.4 are identical or different and denote hydrogen or C.sub.1 -C.sub.6 alkyl groups, PA1 R.sub.5, R.sub.6 and optionally R.sub.7 are identical or different and denote hydrogen or C.sub.1 -C.sub.4 alkyl groups, PA1 X denotes the carbon atoms necessary to complete a benzene or naphthalene ring, and PA1 n is 1. PA1 R.sub.1 denotes hydrogen or a methyl group, PA1 R.sub.2, R.sub.3, R.sub.4 denote hydrogen, PA1 R.sub.5 denotes hydrogen, a C.sub.1 -C.sub.4 alkyl group or a halogen atom, PA1 R.sub.6 denotes hydrogen, a C.sub.1 -C.sub.4 alkyl group, an aryl group or halogen, PA1 R.sub.7 denotes hydrogen, PA1 X denotes the carbon atoms necessary to complete a benzene or naphthalene ring, and PA1 n is 1. PA1 R.sub.9 denotes an alkyl, alkoxy, alkoxycarbonyl, acyl, acyloxy, aryl, aryloxycarbonyl, formyl, cyanide, carboxyl, hydroxyl or aminocarbonyl group, and PA1 R.sub.10 denotes hydrogen, halogen or an alkyl group. PA1 R.sub.8 denotes hydrogen, PA1 R.sub.9 denotes a C.sub.1 -C.sub.4 alkyl group, a C.sub.1 -C.sub.8 alkoxy group, an alkoxycarbonyl group containing 2-13 carbon atoms, an acyloxy group containing 2-18 carbon atoms, an aryl group containing 6-10 carbon atoms or an aryloxycarbonyl group containing 7-11 carbon atoms, where the aryl groups may be substituted by hydroxyl grouos, and PA1 R.sub.10 denotes hydrogen or a methyl group. PA1 a) those containing at least one orthocarboxylic acid ester and/or carboxylic acid amide acetal grouping, in which the compounds may also have a polymeric nature and the said groupings may occur as linking elements in the main chain or as lateral substituents, PA1 b) oligomeric or polymeric compounds containing repeating acetal and/or ketal groupings in the main chain and PA1 c) compounds containing at least one enol ether or N-acylaminocarbonate grouping.
1) a compound forming strong acid when exposed to actinic radiation, and PA2 2) a compound containing at least one acid-cleavable C--O--C bond
The invention also relates to a radiation-sensitive copying material comprising alayer support and a radiation-sensitive mixture deposited thereon.
Positive-working light-sensitive mixtures are known and have been described for a wide variety of possible applications such as the production of photoresists or photographic printing plates.
The properties of these copying layers are largely determined by the main component in terms of quantity of the light-sensitive mixture, the binder. As binders for positive copying layers use is almost exclusively made of phenol-formaldehyde or cresolformaldehyde condensation products of the novolak type. For some applications of positive copying layers, however, the properties resulting therefrom are not optimal. This relates, in particular, to the heat resistance in the case of photoresist applications and the level of print runs in the case of use as lithographic printing plates. It has been found that a generally better property profile results from substituting binders with higher glass transition temperature for the novolaks. Thus, a whole series of alkali-soluble binders for positive copying layers have been described, such as, for instance, phenolic resins based on naphthol (U.S. Pat. No. 4,551,409), homo- and copolymers of vinyl phenols (DE-A-2,322,230, corresponding to U.S. Pat. No. 3,869,292 and DE-A-3,406,927, corresponding to U.S. Pat. No. 4,678,737), polymers of the esters of acrylic acids with phenols (Japanese Published Specification 76/36,129, EP-A-0,212,440 and EP-A-0,212,439) or copolymers of hydroxyphenylmaleic acid imides (EP-A-0,187,517).
Binders of the type mentioned have, however, hitherto not been able to find practical application. One reason for this is that these polymers do not satisfactorily fulfill an essential requirement which is imposed on binders of positive copying films: that of the possibility of thermal self-crosslinking. This property, which exists in the case of novolaks, is of importance if the copying layer has to withstand aggressive chemicals. In this respect it is also known to incorporate units in the polymers which, although they are not alkali-soluble, facilitate the thermal crosslinking (EP-A-0,184,044). As a result of this, however, other properties such as the development behavior and the storage stability of the mixture are impaired.